InfoPath Dev

I have a FormsViewer document library that was created from an InfoPath template and published with Promoted Properties. Since this is on-prem, a JavaScript redirect in the Web-Part causes the form to operate as a FormsViewer form. The client now wants the Manager E-mail address to appear in one of the automated e-mails, but that field was not initially promoted when the document library was created. I went into the form (FV) template and added the Manager E-mail as a promoted field and published to FormsViewer, but this new field is not showing up as a promoted column in the document library and therefore not eligible as a Lookup for my e-mail. How can I make this happen?

You will need to either republish your form to the Form Library, or use the newer version of Forms Designer to add the promoted property. It looks like the ability to add and publish promoted properties in Forms Designer has been there since 2022-01-10 and I think you've said you are on Forms Viewer 7.4, so hopefully you can click the Design button on your Forms Viewer template and add this promoted property in Forms Designer rather than having to publish directly to the library!