I open the "new panorama" tool in affinity photo 2.2.01931 beta for Windows. It is (still) not possible to drag and drop pictures into this window from an other image catalog application.
There is no projection choice in the panorama tool, as far as I can judge spherical projection is used. Planar, Cylindical projections are needed. There should be a simple tool to straighten the resulting image without complicated transformation.