This may take awhile, but you could get a few insects frog the outdoors that are not poisonous and the are about the right size, then breed them for a few generations and feed those offspring. They should then be frog safe. Another option, if your frog was wild caught in the first place, is just get insects from outside if you can be sure that there are no pesticides used in the area
Sent from my SM-N900V using Tapatalk