Need help permission denied (AdGuard installation)

Hello I like to install adguard I followed this guide

But when typing

/opt/adguardhome/adguardhome -s install

I get "permission denied" maybe it's something simple but I'm lost

You likely missed doing...

chmod 755 /opt/AdGuardHome/AdGuardHome

I did this one?
If I check in winscp the directory has 755 also the adguardhome file has 755

Since Linux is case sensitive, and the references in that tutorial are to "AdGuardHome", you may have issues with your naming "adguardhome".

I copied and past the line but still no acces

I used another command line and now it works, adguard started to install but why???