How to add FEDERATION_SERVER to stellar.toml

The important to define the FEDERATION_SERVER  before any others sections

# stellar.toml example asset
# Federation service provided by StellarID.io
FEDERATION_SERVER="https://stellarid.io/federation/"
[[CURRENCIES]]
code="GERSH"
issuer="GD5NE236O2MQTHADAU3T5JNDKAEV2HCCR75MBISLNMG6IRTKI3M26UCK"
display_decimals=8
name="Gershon Test"
desc="1 GERSH token entitles you to a share of revenue from Elkins Goat Farm."
conditions="There will only ever be 200000000 GERSH tokens in existence. The 100000000 will be distributed as 2500000 accross 5 years"
image="https://crypto-il.club/crypto_il-logo.png"