Final septic tank connection

[G3_DIY]

Hello plumber Nation,

We're making the final trunk line connection to our newly installed concrete septic tank and I need some assistance. When looking into tank where waste line enters tank, there's a 4 1/2 inch concrete square inlet area. Do I position the pipe to dump into that (seems like a very small area for all waste to enter tank without risk of clogging up eventually)? Also, someone suggested cutting end of pipe on 45° angle facing down to better direct flow into tank. Any guidance is much appreciated. I'll attempt adding picture for clarity. Thx in advance....