Adding cataloger name in delivery note form

Hello

How to add a cataloger name in delivery note form under ‘Cataloguer’ field? Please refer attached image

I have tried adding from customize form option but it didn’t it.

What is Cataloguer? New doctype or just a dropdown with static values? And also share screenshot what you have done.

Cataloguer is label name on delivery note form with select type. I tried adding it under ‘options’ below, however it seems hesitant.

Add it as a Custom Field.