"Based on the current timeline, builds that use JCenter will be able to resolve dependencies until February 1, 2022 without changes. After that date, there are no guarantees that you will be able to build your software if you continue to use JCenter." from https://blog.gradle.org/jcenter-shutdown
The recommendation is to publish these packages to maven central.
Some helpful documentation for doing so:
https://blog.sonatype.com/dear-bintray-and-jcenter-users-heres-what-you-need-to-know-about-the-central-repository