Ok I’m a little confused as to why you think this frog is ill or dying. Again, in the photo I see a healthy and content wild frog that frankly looks better than most captive frogs of the same species. The best thing you can do for it is to leave it be. We’re not talking about a captive frog in your care. Nor are we taking about a wild frog that has sustained any obvious injuries. I’m sure your heart is in the right place but given the circumstances again I’d advise you not to stress the animal out. It’s normal for this species to bask. It’s engaging in a completely normal behavior.