How do I make objects not spawn inside a certain radius (Inside of a random spawning radius)

(SCROLL DOWN FOR ANSWER) I want objects to NOT spawn inside of a certain radius (Players View which is +/-20 on x & z). How would I make it exclude this area. Since the player will move it should not be a fixed position but should move with the player. Please TRY to keep answers somewhat simple if that’s possible!
(Also, please tell me how I could make the spawn radius follow the player so the zombies can spawn closer to the player and not 400 meters out)

    //Array of different zombies
    public GameObject[] zombiePrefabs;

        //Spawn Timer
        float startSpawnDelay = 3.0f;
        float spawnTimeDelay = Random.Range(1.5f, 3.5f);  
        //Spawn Timer---------------------------------------
        InvokeRepeating("SpawnRandomZombie", startSpawnDelay, spawnTimeDelay);

    void SpawnRandomZombie()
        if (detectCollisionsScript.gameOver != true)
            int zombieIndex = Random.Range(0, zombiePrefabs.Length);
            Instantiate(zombiePrefabs[zombieIndex], RandomSpawnPos(), zombiePrefabs[zombieIndex].transform.rotation);

    Vector3 RandomSpawnPos()
        float spawnPosX = 20f;
        float spawnPosZ = 20f;
        float spawnPosY = 0;
        Vector3 spawnPos = new(Random.Range(-spawnPosX, spawnPosX), spawnPosY, Random.Range(-spawnPosZ, spawnPosZ));
        Vector3 playerPosDifference = spawnPos + player.transform.position;
        return playerPosDifference; //Here is where I'm having trouble with spawning the zombies

Diagram of what it should be

Green is where the enemies can spawn (+/- 23 x/z)
Red is where enemies can NOT spawn (+/- 20 x/z)

I did end up fixing this so if anyone if the future is reading this, this is the code I used (It is quite long and could be optimized) :

my idea is to randomize which area the zombies will spawn, is it left or right excluded area and front or below excluded area.
then using instantiate for each area.

int RandomArea = Random.Range(0,4

if(RandomArea == 1) //say this for left exclude area
Instantiate(zombiePrefabs[zombieIndex], new vector3(-spawnPosX, "Left of Excluded Area", spawnPosY, Random.Range(-spawnPosZ, spawnPosZ)), zombiePrefabs[zombieIndex].transform.rotation);

and so on for other area

A simple solution would be to get a random position THEN push it away from the player by the needed distance
something like this

Vector2 randomPos = MethodToGetRandomVec2();
Vector2 playerToRandomPos = randomPos - player.transform.position;
float radius =  2;

return radomPos + (playerToRandomPos.normalized * radius);