Channel configuration looks fine.
The Utelred_bot that you specify as recipient - is it the same bot that you use for notification sending (the AuthToken is from that bot?).
If it's a different bot, I am not sure, if one bot can send messages to another. But generally recipient should be a name of either a group, channel or username. Or, second option, recipient could be numeric ID of group, channel or chat.
Try to send a message to your telegram account. For this in your telegram profile you need to set a username. Then you need to send a message from yourself to the bot (bots can not initiate dialogs). And then try to send notification to your username (without @) from NetXMS.
The Utelred_bot that you specify as recipient - is it the same bot that you use for notification sending (the AuthToken is from that bot?).
If it's a different bot, I am not sure, if one bot can send messages to another. But generally recipient should be a name of either a group, channel or username. Or, second option, recipient could be numeric ID of group, channel or chat.
Try to send a message to your telegram account. For this in your telegram profile you need to set a username. Then you need to send a message from yourself to the bot (bots can not initiate dialogs). And then try to send notification to your username (without @) from NetXMS.