Hi @Dan_Ndori
welcome to the forum! Please introduce yourself here!
Hardcoding any url in the app would require implementing changes in the code and preparing your own version of ODK Collect. If you are not a developer you would need to hire someone to do that.
It would be easier to use QR codes. If you want to do that you will need to prepare one device adding the url and all the other settings you want and then let other users to scan your code.
https://docs.getodk.org/collect-import-export/#