Connect a payment account and any invoice can carry a payment link. Your member opens it and pays by Pix, card or boleto, and the invoice settles itself when the money lands. The money goes to an account in your own business’s name: Zenly never holds it and takes no cut of it.
Only the owner can do this, in Settings → Payments. It opens a real financial account in your business’s name, so it asks for real details.
Charging online opens when all three have cleared, not before and not partly. Approval is what unlocks Pix specifically, and an account that could only issue boletos would be worse than not having one, so Zenly waits for the whole thing rather than handing you half of it.
Open the invoice and choose Request payment. This is per invoice on purpose: a gym has a card machine at the counter, and an invoice that quietly minted an online charge as well would leave a live charge against somebody who already paid you in person. Connecting an account makes the link possible, never automatic.
The link asks for what is left, not what the invoice was for. Take R$600 of an R$1.800 sale at the desk and the link asks for R$1.200. Lost or expired links are fixed by asking again with New payment link; the newest one is where the member is sent. The link appears in the member’s portal as well, so they don’t depend on finding an email.
A member with no CPF or CNPJ on file can’t be charged, because the provider will not raise a charge against somebody it cannot identify. Add the document to their record and try again. An invoice that is already paid, void or refunded is refused too, since asking for money on a settled invoice is the one mistake worth blocking outright.