You can flash the original firmware or extract bmminer file from a regular machine and use it with the deployer.

https://file11.bitmain.com/shop-product/firmware/Antminer%20T9%2B/Firmware/00720181126222105736ja7USR1p0695/Antminer-T9%2B-all-201811211435-autofreq-user-Update2UBI-NF.tar.gz