i've try to open connection with local DB SQL Server Express Edition v2019 (the SQL Server is installed on the same computer where i execute Node-Red).
I've download and install a node-red-contrib-mssql-plus-0.12.2; then i try to the DB configure connection.
The server name are "NODE-RED\SQLEXPRESS", port 1433, table name "TblNodeRed". Then i've create a user: name and password equal to "nodered" (see the picuture).
The SQL firewall roules and port configuration may be ok (see the pictures).
PS, just noticed you set the default port to 1433 so that might be ok (but still check SQL server logs)
More importantly, remove the instance name from the Server field. Also, instead of the DNS/WINS/HOST name, try using the IP of the machine running SQL Server. Something like 127.0.0.1 or 192.168.86.1.10 only.
Also, read the full threads I linked to (some valuable info in them).