How to install an ‘apk’ on a TCL Flip Go (AOSP version 11)?

Was wondering how to install an ‘apk’ on a TCL Flip Go (AOSP version 11) phone? I already tried to turn on USB debugging mode in order to install an apk with adb. But unable to follow the instructions for enabling USB debugging for a TCL Flip phone (here: https://www.tcl.com/global/en/support-mobile/faq/7541) because there is not a Build number field and entry in the About Phone section. As well, tried to follow the instructions here: https://github.com/neutronscott/flip2/wiki . But when running python3 mtk-bootseq.py FASTBOOT /dev/ttyACM0 (used ttyACM0 as that is what would pop up for the flip phone when running dmesg -w) upon the phone booting it would be able to send serial messages for a second or so then not be able to send.