I think this will do what you want in essence:

1. 
   int iDatum;
   
   void setup() {
   
     //choose a point 5,000 milliseconds in the future 
     iDatum=millis()+5000;
     ellipse(width/2, height/2, 10, 10);
   }
   
   void draw() {
   
   
     //is it now time?
     if (millis()>=iDatum) {
       ellipse(random(width), random(height), 10, 10);
       //choose another point 5 seconds hence...  
       iDatum=millis() + 5000;
     }
   }
   
   

the way is to store the time and compare to current time

1. setup()
2.   timeSinceLastLetter = millis();

and in draw

1. draw()
2.     if (millis ()- timeSinceLastLetter >= 3000) {
3.       timeSinceLastLetter = millis();
4.      ..............
   

ups, I was too slow

sorry Chrisir!

Okay, It's repeating now thanks:)

I fixed it, nvm:) Thanks for the support!