

Not sure how yours works, but on some “remote-only” devices you can use a (potentially sketchy) USB split cable with power connector and an additional USB port for a keyboard / keyboard-mouse combo so you can use a regular browser to download and install apps.
Something like https://flathub.org/apps/com.github.jeromerobert.pdfarranger to crop pages might work, or https://flathub.org/apps/net.sourceforge.Pdfedit (old and possibly insecure) for more options.