If you do that in the SQL Console of DNN you should use
SELECT 'sp exists'
instead of the print command, as the SQL Console does not return anything when you use print. And you should use the code above from there, and not from SQL Server Management Studio (SSMS).
The {databaseOwner} and {objectQualifier} tokens are DNN-like SQL syntax. In fact they correspond with the values in the web.config file that you find in this line:
<add name="SqlDataProvider" type="DotNetNuke.Data.SqlDataProvider, DotNetNuke" connectionStringName="SiteSqlServer" upgradeConnectionString="" providerPath="~\Providers\DataProviders\SqlDataProvider\" databaseOwner="dbo" objectQualifier="" />
The tokens are replaced by these values automatically. The background of this is the use of shared hosting installations, where you could use different DNN installations with only one database, but different object qualifiers (the need for that is low nowadays), or schemes. In the case above, {databaseOwner} will be replaced by "dbo." and {objectQualifier} by an empty string. If you manually replace that you get a statement that you can use in SSMS. Also the installer uses this syntax, so you have to use it in your manipulated .SqlServerProvider file.
For the requirements see DNN Platform Requirements -- DNN Docs (dnncommunity.org). But anyone should drop the lines from SQL Server 2012 and 2014 for DNN 11.1.
Anyway, SQL Server 2012 - 2017 are after the end of mainstream support (see Microsoft SQL Server Versions List (sqlserverbuilds.blogspot.com)), so upgrading is a must, not only for security reasons.
Happy DNNing!
Michael