You can enable the RMA features in customer account using :
To allow customers to request a new RMA, enable also option “Enable request”
Once it’s done, customer can see a new “My Returns” tab in frontend of customer section.
From this tab, he can consult returns history and get details.
From the returns tab, customer can ask a new return using the “Request for a return” button.
The next step is to select the order to return : you can control what orders are visible here configuring the allowed statuses in stores > configuration > boostmyshop > rma > front > Allowed order statuses
Once the order is selected, customer can select quantity to return for each products, but also the reason, request and additional comments : you can configure the available reasons & requests in stores > configuration > boostmyshop > rma > General.
Once the request is submitted, it creates a new RMA with status “Requested”, and an email notification is sent to admin (the admin email address is configurable in stores > configuration > boostmyshop > rma > admin notification)