To the host, respectfully, what you have arranged to have participants do is called a Rensaku, which is linked Tanka. This can consist of two Tanka, or dozens, depending on how many haijin participate for however much time. Tanka is 3 + 2 lines with sound symbol count (not syllable) of 5/7/5/7/7.
On the other hand, a Renga is linked Haiku (which are not written the way the examples here have been written that are more Tanka in expression. To do more traditionally correct, you need to adjust the guideline you set, plus make the challenge an endless competition without a deadline, and without a solitary winner.
I hope this helps. Thank you **bows**, and welcome to DUP.⛩