First, check your site status via WP if on it. Tools>Site Health>Info [second tab at top]. Go to Server Section and note the current max settings.
Go to MT, Login, Go to the blue Admin on the Uncle Jake Media LLC VPS
Click on Launch WHM
Click on List Accounts or Search for it.
Login to Cpanel and look for the Software section and choose Multiple php.ini editor
From the drop down, select the domain option, not Home directory.
Edit the settings there. The image at the top of this article showing the Server settings in WP has some good options to select.
Go back to Tools>Site Health>Info in WP to verify the settings took.