1. Launch Exchange Admin Center
Click on start and then expand Microsoft Exchange Server 2019. Click on Exchange Admin Center.
2. Login to Exchange Admin Center
At the main EAC page, enter in your username and password and then click on sign in.
3. Click Servers
Once logged into the EAC, click on Servers on the left hand side.
4. Click on Certificates
On the right hand side, click on Certificates at the top.
5. Select Server
Once you have clicked Certificates, the page will open and show a server with a drop down list. Select a server and then click the 3 dots (...) and choose Import Certificate and then enter the location and password.