Huawei Tablet deleted OS

I have a Huawei tablet model # S7-303 u i was trying to do a factory reset on it and some how i ended up deleting the whole Operating system now i don't know what to do. Its stuck on the T mobile springboard screen.. i know how to get into the TWRP mode but i don't know what to do from there or where i would be able to download the OS to install.. can someone please point me to the right direction i would really appreciate it..

Thank You in advance