Sharepoint List - Column Permissions

Hi Everyone, 

Context: creating an internal job board where leadership submits a form (job) and it flows to a list. One of the columns is an "Action" column where employees can click a JSon button to "Apply" which triggers a Power Automate flow (approvals).

My problem is that the flow picks up "Modified by" Details for the approval flow (i.e applicant applies, flows through to job poster to review applicant) but this means I need to give the applicants edit access, which is not ideal as they can then edit the entire row item (job posted).

How do I ensure they can only click "apply" and not have edit access to any other column.

I have used a view to narrow the fields down, also removed the commandbarpromps using JSon formatting. My list is embedded on the main page (could not use the list webpart as the JSon button can't be clicked then). 

I've seen some solutions using SPFx but have no clue how to fo that nor does my company allow such.

Open to alternate solutions as long as the objective is achieved (people can apply)