First, if you have your own domain name, setup a subdomian called pca.YOURNAME.tld and request SSL for it. Ask your hosting provider.
If not, request SSL certificate for YOURNAME.bislinks.com from https://pcafree.bislinks.com
Assuming, you have downloaded YOURNAME.TLD.pfx file to your computer, e.g., to C:/Users/USER/Documents from your hosting provider.
Open IIS as Administrator
Under Connections, Click on your main IIS Server Connection, usually your computer name
In the middle pane, double click "Server Certificates"
Under Actions, click 'import'
In the 'import certificate' dialogue, under 'certificate file .pfx,' select location `c:/Users/USERNAME/Documents`
and select .pfx file you just downloaded
Open IIS as Administrator
Under connections, selet your site
Under Actions, click bindings
Under Actions, click bindings
Under Site Bindings, click add
Under Type, select https
Under IP Address, Select "All Unassigned"
Under Port, leave it as `443` or assign a custom port above 10000, e.g., 21202 or 20443 or 30443 or 40443
Under SSL Certificates, Select `YOURNAME.TLD`
Check "Disalbe HTTP/2" in order to disable http2
Clcik OK to save
Click close to close Site Bindings.
Open IIS as Administrator
Under connections, selet your site
Under Actions, click bindings
Under Site Bindings, Select https and click edit
Check/enable the "Disable HTTP/2" option