If the app can be used after 10 months?

we want to buy this app, but we the maintenance time is only 10 months, so we want to know if it is able to be use or not after 10 months.

Are you using Jira Cloud, Server or Data Center?
If you are using Jira Server, the license end date will be prorated until 15 Feb 2024.

we are now using server License(not cloud or DC), so if we can use it after 15 Feb 2024 normally?

You can find more details about Server end of support on this page.

After the end of support date, Atlassian and Marketplace Partners will no longer provide technical support for any issues, security updates, or bug fixes for critical vulnerabilities. Regular security updates help protect your business from threats and vulnerabilities, so we recommend moving to our Cloud or Data Center products before the end of support date.

thanks for your information.
we know the risks and now are trying to study to upgrade to DC product.
If we ultimately decide not to upgrade, we know that we will not receive any technical support beyond the allotted time. However, we wanted to know if the app would still work?

It depends. Some apps are perpetual as long you don’t upgrade the version. Some apps requires an active maintenance subscription to continue to work.

You may want to check with Tempo to confirm.