The EzUHF is a legacy ImmersionRC product that has not been produced since 2016.
The last firmware published for the EzUHF is v1.53, which was released in 2016.
This firmware is available from here.
https://www.immersionrc.com/fpv-products/ezuhf-8-channel-diversity-receiver/
Limited support is available for this product at this point, but there is a wealth of information available online, in various forums, and social media sites.