hey guys, is it possible to display the approve button on PO to the buyer roles? currently it is only displaying on purchase orders under the Admin role only

I would try Customizations -> Scripting -> Scripted Records and see if there is a workflow on the PO that hide's the button by role

Is a native role or a custom one?

looks like a native role

Then yes, seems to be a Workflow or script Customization > Scripting > Scripted Records Look for Purchase Order and see what customization it has