How can I store user input from a Velocity Template into a Active Object

I want to create a velocity template consisting of a few fields to use in a web-panel for the view-isssue screen. The fields should contain information retrieved from a Active Object Entity. The user is then able to change the values inside these fields. If there is no data stored ub the Active Object for the current issue the user input will be stored as a new entry.

So basically I want to update the values in the Active Object Entity with the new values entered by the user in a Velocity Template for a web-panel. Is this possible and if so how can I achieve this?

I have looked at servlets and web actions but as far as I know I can’t put these inside a web-panel. I also don’t know how I can use custom fields inside my web-panel so as you might be able to guess progression with this topic is slow.

I figured out I need to use the Rest API to do this but I’m still having trouble. I have created a new topic here to ask for help with the Rest API: