Heya,
Do you have any modifiers? Umbrella? Softbox? And a CTO gel of differing values? If you do, I'd use that. Largest modifier you can find, and get it as close as you can out of the frame to subject. Gel can be a 1/4th or 1/2 CTO and work fine here with your ambient temp.
If you do not have those things, get them.
If you do not want to get them, bounce the flash off a large wall and drop the flash exposure a bit so it's fill, as you have it now, it's acting as key and making harsh shadows and is of course a much cooler temp than ambient.
Maybe pull the chair forward a few more feet to get more isolation to get nicer, bigger bokeh balls on that tree?
Very best,