Set Tile Package as Basemap for AGOL Webmap

ZacharyUhlmann1

I've uploaded a tile package and published to ArcGIS Online.  Now I'm trying to format the webmap for offline use in Field Maps with sideloading.  That's ancillary - the issue is how do I add the tile layer as a Basemap from the basemap gallery.  I don't see it in the basemap gallery, my only option is to add as a feature layer.  However, in Field Map Designer, I can't designate this as a basemap because it's not...a basemap in the webmap.  I understand for offline purposes I can provide the filename of the sideloaded tilepackage, but this deviates from ESRI's instructions.  Can I add my own tile layer as a basemap?  

Essentially, can my Tile Package replace World Imagery:

Thanks.

RhettZufelt

add the tile layer to a map viewer, save it and share web map to your basemap group.

you should then be able to add/use it as a basemap.

for the sideloading in Field Maps App, transfer the tile package locally, then in Field Maps Designer, you can set the name of the tile package in the offline settings:

R_