Q: I don't have access to my old phone number associated with apple keychain to receive the validation code !!

I don't have access to my old phone number associated with apple keychain to receive the validation code !!

they told me that I need to set up a call from apple support or something but I dont know how to do that+I've tried to do it but also faced a page where it says I have to pay for the support call ?

all what I need to is change the phone number thats all ,