Establish FMV for farmed crypto when there is no market

Hello, I am looking to understand how a fair market value is established when while during farming there wasn’t 1) any market available 2) technical restrictions in place that prevented any coin transfers. My concern is about US taxes.

Context, the Chia blockchain launched on March 19th 2021. Between the launch date and May 3rd 12:30 EDT no transactions were supported.

How does one establish a FMV for Chia tokens farmed during that period?

And even after May 3rd the options of exchanges available to US residents including the day of this posting are very limited. The daily trading volume is very low. Can a fair market value be established?

PS: In Chia terms, farming is used for the process that’s otherwise referred as mining.