Ical and airbnb don t sychronize

Hello and thank you for this awesome plug in,

i tried to synchronize the calendar of an accommodation with the airbnb but my way seems to not working.
I copy the link location from the plugin and then paste it to the airbnb but i get the message that the “there is a problem with synchronization, re-enter the url”. Is there something that i am doing wrong?
Thanks you in advance!