Most Stellar wallets use the same principles when adding trustlines.
One of the easiest methods is to signup at stellerport.io and create an account
Save your recovery phrase
Activate the wallet by sending XLM or another crypto asset (recommended 2-10 XLM)to your new address
Once activated, go to Deposit and enter FRED in the searchbox, you will see our logo with the domain fredenergy.org (beware of similar tokens with the FRED name and check for our logo or issuer address GCA73U2PZFWAXJSNVMEVPNPPJCZGETWPWZC6E4DJAIWP3ZW3BAGYZLV6
Click next and you will be asked to add the Trustline
Click “Add FRED Trustline”
That’s it, you will now be able to send and receive FRED tokens.
For Lobstr and some other wallets you will need to use our domain, fredenergy.org which should have the issuer address of GCA73U2PZFWAXJSNVMEVPNPPJCZGETWPWZC6E4DJAIWP3ZW3BAGYZLV6
Further Lobstr instructions can be found here https://lobstr.zendesk.com/hc/en-us/articles/360007280774-Adding-custom-assets-in-LOBSTR
If there is any other issue, just Google it as Stellar and trustlines are nothing new.