Metadata - How to update summary in a layer within a service

[Marokapara]

Hi AGOL community,

I thought this would be easy to do, but I've come across a road block.

I'm doing some housekeeping and want to update the summary in a feature layer within a feature service, but there's no pencil/edit option. How do I fix this? Is this permanent from when I shared from ArcPro? Do I  have to go in the json to change it?

Thanks in advance for your help.