Does Jexo have some demo environment to access and try the Suri app?

You can create your own test environment by creating a free Jira instance Software.  Afterward creating the free Jira instance, you can install Suri from the Atlassian Marketplace.

Both Jira Software and Hedge are free for up to 10 users, so you can invite 9 other colleagues to try Hedge for as long as you need.

For more info, Get started with Atlassian cloud for free, Suri - Portfolio Project RAG Reporting for Jira.