Exchange are being constantly developed, each with new ideas and added to the long list of exchange already available. It is no doubt that some are absolutely a no go area and some are very inefficient. It is good to make a critical research on any exchange you are trying to opt into.
The ontrade exchange was introduced or launched in 2019. The exchange has been functioning for sometimes, some couple of months, they have not been effective, they went offline for an upgrade. This is exchange is not accessible at moment as it is under maintenance or upgrade and will be available soon. Untill they make a public anouncement of their reopening, it is advisable you stay away from this Exchange. I recommend you avoid anyone contacting you claiming to be a part of the team on social media platforms as it is fraudsters.