iDeco account – where to open?

Hi, as the title says I am looking to open an iDeco account for the first time and I am not sure where to. I am considering SBI, so guess first I need to make a bank account there and then proceed with iDeco? I also have a NISA account with PayPay. Would you all suggest me opening a new NISA account with SBI and delete the one with PayPay? Thanks.

by worried_alligator