I've got the Ringke Fusion-X case, an H9 screen protector and some cheap USB-C port plugs from Amazon. Not water/dust proof at all but still better than nothing.
You can always get some of these?
https://smile.amazon.com/PortPlugs-Silicone-Compatible-Samsung-Cleaning/dp/B078NGJPM9/
I used these because 95% of the time, I am using a Wireless Charger. The only real times I use the charge port is for large data transfers or in the car.
I have the official Samsung Leather case on mine and these fit flush.
I got these to hopefully prevent what happened to my Pixel 3: PortPlugs USB c Port Plug (10 Pack), Dust Plug Compatible with Samsung Galaxy s21, s20, Plus, Ultra, Note 10, Pixel, MacBook, USB c Dust Cover for Android, Includes Cleaning Brush (Black) https://smile.amazon.com/dp/B078NGJPM9/ref=cm_sw_r_apan_glt_fabc_G3PW7TRV0HY5DD4J4CJ5?_encoding=UTF8&psc=1