Issue with Uninstall

[PerfectMelancholic]

At some point I installed bigsurblocker and now that I tried to completely uninstall it I am getting this:

/Library/LaunchAgents/com.hjuutilainen.bigsurblocker.plist: Could not find specified service
Could not find service.
rm: /Library/LaunchAgents/com.hjuutilainen.bigsurblocker.plist: Permission denied
Unknown error Error Domain=NSCocoaErrorDomain Code=513 "“com.hjuutilainen.bigsurblocker.bom” couldn’t be removed because you don’t have permission to access it." UserInfo={NSUserStringVariant=(
    Remove
), NSFilePath=/var/db/receipts/com.hjuutilainen.bigsurblocker.bom, NSUnderlyingError=0x7fba35418530 {Error Domain=NSPOSIXErrorDomain Code=13 "Permission denied"}}.
Forgot package 'com.hjuutilainen.bigsurblocker' on '/'.

What am I doing wrong? It might be stg obvious to you that I am missing perhaps not running it with sudo u mention in the uninstall section but I am not quite sure how to do that. Would greatly appreciate your help.