How can customer convert and estimate and pay the order

I would like to put an event into a quote and have a button for the customer to create the invoice by themselves.

You can let your customer log into their account in order to create an invoice and pay for it.

When a buyer logged in > go to 'My Account' > you'll see a page just like this:

Then scroll down to the 'Quotes & Estimates' box - you can see there are 2 options for you to either 'view' or 'pay' for an estimate: