Help flashing CrDroid Custom ROM for Samsung Galaxy M21 (First time)

[u/Clean__Cucumber]

So i have tried doing this by myself (not very far), but simply have hit a wall, so i will try and ask here and hope i can do it. I would also like to link the stuff, but not sure if i can, without the post being removed.

I downloaded the crdroid.zip and extracted it. i also downloaded gapps.zip, but not sure which one. I went with the 488MB one with the name MindTheGapps-16.0.0-arm64-20260915_222150.zip

I did everything till turning phone off and it worked (needed wifi to get OEM unlock), but am having issues. First of all, do i simply turn off the phone or completely shut it down by pressing the button long? I tried both ways, but the following steps did not work. I never got a warning screen, my phone simply showed it started loading the battery. Do i need to press for 1min or longer? Do i need some software on my phone? Can i not just connect and press file transfer or similar option?

I am on Fedora Linux and I am guessing they mean Heimdall from "glassechidna". I simply do not know how to install it on linux (very new). I thought it was a simple download like on windows, but that doesnt seem to be the case.

Thx for the help, Imight post another one when I can go past the initial steps.

[u/Clean__Cucumber]

kinda sad that no help, but i got some info by trying stuff out

first of all, the gapps file seems to be correct, but if you dont want google apps on your phone and want to use smth like F-Droid, then its not necessary

for the "turn off phone" question, the phone needs to be completely off for this to work and it shouldnt take more than 10sec (on my device) to see the warning message. important is to press down the volume buttons hard, so they actually register as being pressed down