[NTECUK]

The letters reference to the shape of the bead seat.
Tubles types have a ridge to locate the bead and then a space were the bead seat fits in.
Some wheels this is either no ridge or too small a gap twix ridge and the edge of the rim.
The side wall can then be pushed off the rim,pop no pressure. Nasty mess.
You can probly see if you have the right shape by eye. but I don't think that the Chinese are in the habit of following international standards so check the complete circumference.
A bit of thick card as a Guage that fits a tubeless wheel be easily made up.
It is your call if you belive it will stay seated