At first I do:
sudo apt install tor obfs4proxy

Then I do this:
sudo gedit /etc/tor/torrc

And add this to the end of config file:
UseBridges 1
Bridge obfs4 28CA5C42872FD6FBEDA9658F2A63618776A54416 cert=GYIbAY5uvHsfB9lBMGOS9/0+nU3uIO+DdxBZsOWwfwZsjUlxz3YIOqFKQg5GRzINiy1jAw iat-mode=0
Bridge obfs4 32EF45EC5ECD3027B6DEE20E2B7D576AD35A8A8E cert=p9L6+25s8bnfkye1ZxFeAE4mAGY7DH4Gaj7dxngIIzP9B tqrHHwZXdjMK0RVIQ34C7aqZw iat-mode=2
ClientTransportPlugin obfs4 exec /usr/bin/obfsproxy

Finally I do journalctl -b --no-pager /usr/bin/tor and get this after file saving:

Can't use bridge at [scrubbed]: there is no configured transport called "obfs4"

What am I doing wrong? Thanks in advance!