distribution/leap/15.3/repo/oss/ - Is it a .repo file?

I want to add following repo:
10:~ # zypper addrepo -r http://download.opensuse.org/distribution/leap/15.3/repo/oss/

Problem parsing the file at the specified URI:
/var/tmp/TmpFile.DL38Rg: Section ]: Line 1 contains garbage (no ‘=’ or ‘:/?|,’ in key)
Is it a .repo file?

What am I doing wrong?
Thank you very much!

To start with, can you please show us current repo list?

zypper lr -d

You didn’t supply the *.repo file which the -r option is for. Try to run the command without the -r option.

Thank you, Atronach!
That worked!