Here you can consult the frequently asked questions of Fertilab's anonymous communication channel
Some tips for achieving maximum anonymity, in addition to informing that the report is anonymous are:
You can use the open source TOR browser, which anonymizes the IP address.
If there is an emergency should I use this channel?
What happens if, later, it is found that the content of a report is false?
When will I receive a response to my complaint or query? What is the resolution deadline?
Where is the platform that manages the channel?