curl https://raw.githubusercontent.com/tumic0/GPXSee-maps/master/World/MapTiler.tpl -o ~/.local/share/gpxsee/maps/maptiler.xml
sed -i 's/insert-your-apikey-here/rJU8f69pSsmhWM7EWEG3/g' ~/.local/share/gpxsee/maps/maptiler.xml
gpxsee
In the logs I get https://api.maptiler.com/tiles/v3/2/1/1.pbf?key=rJU8f69pSsmhWM7EWEG3: Operation canceled after what seems like a time-out ; but curl https://api.maptiler.com/tiles/v3/2/1/1.pbf?key=rJU8f69pSsmhWM7EWEG3 -o a.pbf works fine.
Is https://github.com/tumic0/GPXSee-maps/blob/master/World/MapTiler.tpl still working for you ?
In the logs I get
https://api.maptiler.com/tiles/v3/2/1/1.pbf?key=rJU8f69pSsmhWM7EWEG3: Operation canceled
after what seems like a time-out ; butcurl https://api.maptiler.com/tiles/v3/2/1/1.pbf?key=rJU8f69pSsmhWM7EWEG3 -o a.pbf
works fine.