Small comment to the @miska post Generating application tokens in Turris OS 3.11
My Android apps said “Invalid QR code” too.
The workaround is generate SVG image without URL encode of “&” character … not use & but only &
The right command for me was:
qrencode "turris://$(ubus call network.interface.lan status | sed -n 's|.*"address": "\([0-9.]*\)".*|\1|p')/luci-static/my_secret_url.token?scheme=http&hostname=$HOSTNAME&board_name=turris" -o /www/luci-static/my_secret_url.svg
Good luck 