I recently bought an asus tinker and would like to deploy the openwrt platform, I’ve read a lot of tutorials on openwrt “add new device”, but I don’t know much about this part, and I would like to know if anyone from this forum knows this to help me make a compilation for asus tinker since dietpi is 100% compatible with asus tinker 
Hmm OpenWRT is a totally different OS with most likely different kernel and firmware needs than DietPi has. I suggest you are asking this on Asus TB specific community forum.
Or OpenWRT forum, as a start: https://forum.openwrt.org/t/asus-tinkerboard/6814/3