I have problem in installation on window server

Hi everyone
Im trying to install the latest version of ojs
On window server and plesk control panel for hosting
I uploaded the files and give them the writing permission
And set up the database probably
And make the direction for the uploaded files
And after press the install it show me an error (500)
I talked to my support team which is hosting my server and the tell my that the system using(using functions that were completely removed in PHP 7.0.)
It is still erroring with testing using MSSQL, still for an undefined function it appears:

[11-Feb-2020 19:13:03 UTC] PHP Fatal error: Uncaught Error: Call to undefined function mssql_get_last_message() in C:\Inetpub\vhosts\alsalam.edu.iq\testj.alsalam.edu.iq\lib\pkp\lib\adodb\drivers\adodb-mssql.inc.php:591

“This function was REMOVED in PHP 7.0.0.”

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