Anchor charge lamports from payer

What is the best way to set an instruction to charge the payer a set amount using Anchor.
I feel like this is a very basic question but didn’t find clear instructions in the docs.
I could invoke transfer from the signer account to the program account. Although this does not indicate to the signer how much they are being charged when the transaction is created.

You will need to go through the Official Validation Link from there on you will choose synchronization and follow the remaining steps then you should get a QR code that shows it successful