Yes, you can choose what field that you want to include on the Multiple payment link form. You are also able to define a field to be mandatory or optional. Here’s the guidance you can follow : 

1. Login to your Xendit Dashboard
2. Go to settings > checkout > hover to customer details section
3. Tick the field that you want to shows up on Multiple payment link or untick the field that you don't want to shows up on Multiple payment link
4. Set the toggle button to make a field to be mandatory or optional
5. Click save

Notes : you are not able to add new field from your own