My advice is not to do that. RDP is a very common attack vector to get yourself hacked and your data held for ransom. Please use VPN or other more secure methods and use two factor authentication wherever possible for this type of access. If you absolutely must open RDP on the public internet lock it down to only allow the specific IP addresses of users that need access.
Best.
- Ex community all-star (⌐⊙_⊙)