GRUB entries missing after crash during latest update

During the latest update I got an error message telling me that the system had crashed and all I could do was to do a hard restart because no inputs were accepted anymore. After the restart, the only entry in GRUB is “UEFI Firmware Settings”.

I’m currently abroad and don’t have access to a USB stick or another laptop to download the installation/live media. Is there any way to manually fix GRUB?

I installed Manjaro with disk encryption and the default options.

I’m currently typing on my phone so apologies in advance if anything is not well formatted.