Hi @VickyB lookup columns are supported in SharePoint, but Power Apps struggles when you have a lookup field which allows multiple selections. In a single selection scenario, the lookup field will appear in your list of fields quite happily. But when you have multi select it returns the data differently, it returns a table of data rather than just a single record.
In my example, my lookup column is called "Test" (imaginitive I know!). So if I have a gallery pushing out the main data in my list, I need a gallery inside that which is going to show the items from my lookup field. You won't be able to use the data source selector for the data source, but you can select the "Items" property, and type in ThisItem.<your field name> e.g. ThisItem.Test. Once you have wired up the gallery, you can then add your controls (labels etc) and then use your field selector as normal. You'll have the option of ID and Value.
