Help! The compiler doesn't see my namespace.

[MIDDLE]

I tried to add esp functions to my cheat, but did not encounter a problem. When I try to take any method from the esp namespace itself, I get an error saying that the namespace does not exist, because the esp file is included.
Here is the ESPManager itself, in which there is an error:

#ifndef ZYGISK_ESPMANAGER_H
#define ZYGISK_ESPMANAGER_H
#include "ESP.h"
namespace ESPManager
{
    std::vector<void *> players;

    void arc(float x, float y, float radius, float min_angle, float max_angle, ImColor col, float thickness);
    void void DrawSkeleton(void *player, ImColor color);

    void Render()
    {
        if (espon)
        {
            clearPlayers();
            for (int i = 0; i < players.size(); i++)
            {
                if (players[i])
                {
                    void *player = players[i];
                    auto health = GetPlayerHealth(get_photon(player));
                    auto money = 0; // GetPlayerMoney(get_photon(player));
                    auto team = GetPlayerTeam(get_photon(player));
                    auto armor = 1; // GetPlayerArmor(get_photon(player));

                    if (health > 0 && team != GetPlayerTeam(me))
                    {

                        auto w2sC = world2screen_c(pos + Vector3(0, 0.9, 0), checker);

                        auto w2sTop = world2screen_i(pos + Vector3(0, 1.9, 0));
                        auto w2sBottom = world2screen_i(pos + Vector3(0, 0, 0));

                        auto pmtXtop = w2sTop.x;
                        auto pmtXbottom = w2sBottom.x;

                        if (w2sTop.x > w2sBottom.x)
                        {
                            pmtXtop = w2sBottom.x;
                            pmtXbottom = w2sTop.x;
                        }

                        auto ray = visiblechecker[player];

                        auto color = ray ? visibleCol : invisibleCol;

                        auto healthL = (float)health;
                        const auto hayasaka =
                            (clamp<float>(healthL, 25, 75) - 25.f) / 50.f;
                        auto hpcolor = ImColor(int(120 + 135 * (1 - hayasaka)),
                                               int(50.f + 175.f * hayasaka), int(80));

                        auto minhpcolor = ImColor(int(120 + 135 * (1 - 0)),
                                                  int(50.f + 175.f * 0), int(80));

                        if (healthL > 100)
                        {
                            hpcolor = ImColor(100, 150, 255);
                            minhpcolor = ImColor(100, 150, 255);
                        }
                        healthL = clamp<float>(healthL, 0, 100);

                        if (outoffov && (ray || !visible))
                        {
                            if ((w2sC.x < 0 || w2sC.x > glWidth) ||
                                (w2sC.y < 0 || w2sC.y > glHeight) || !checker)
                            {
                                constexpr int maxpixels = 200;

                                int pixels = maxpixels;


                                ESP::arc(glWidth / 2, glHeight / 2, 226 + distance * 2,
                                    angle - size,
                                    angle + size,
                                    ImColor(1.f, 1.f, 1.f, 1.f * opacity), 4.f);

                                if (oofvis)
                                {
                                    ESP::arc(glWidth / 2, glHeight / 2,
                                        220 + distance * 2, angle - size,
                                        angle + size,
                                        ray ? ImColor(0.1f, 1.0f, 0.1f, 0.5f * opacity)
                                            : ImColor(1.0f, 0.1f, 0.1f, 0.5f * opacity),
                                        1.5f);

Here is the esp.h with the ESP namespace:

#ifndef ZYCHEATS_ESP_H
#define ZYCHEATS_ESP_H

using namespace std;

extern int glHeight, glWidth;
#include "functions.h"
namespace ESP
{
        void *get_boneget(void *player, uint64_t bonefield)
        {
                return *(void **)((uint64_t)get_bipedmap(player) + bonefield);
        }

        inline void arc(float x, float y, float radius, float min_angle, float max_angle, ImColor col, float thickness)
        {
                ImGui::GetBackgroundDrawList()->PathArcTo(ImVec2(x, y), radius, Deg2Rad * min_angle, Deg2Rad * max_angle, 32);
                ImGui::GetBackgroundDrawList()->PathStroke(col, false, thickness);
        }

        void DrawSkeleton(void *player, ImColor color)
        {
                if (GetBones(player))
                {

Here is the compilation error:

/main/cpp/ESPManager.h:228:33: error: use of undeclared identifier 'ESP'
                                ESP::arc(glWidth / 2, glHeight / 2, 226 + distance * 2,
                                ^
/src/main/cpp/ESPManager.h:235:37: error: use of undeclared identifier 'ESP'
                                    ESP::arc(glWidth / 2, glHeight / 2,
                                    ^
/src/main/cpp/ESPManager.h:281:33: error: use of undeclared identifier 'ESP'
                                ESP::DrawSkeleton(player, color);