Mutual Certificate Authentication (mTLS)

Good afternoon, I want to make calls to an app provided by a Brazilian bank. This api will return the customer’s bank statement. However, the bank requests mTLS authentication using an A1 digital certificate. I managed to configure the certificate on the server (bank app). I’m not sure if I need to configure a file to be sent through my call, or if I configure the certificate in Cloudflare for my domain. As I have never used this type of certificate, can anyone please guide me? I am available to provide any further information as necessary.