In order to configure CPU and memory limits for tempo-worker charm, you need to set the new limit values via juju config. By default, the configuration properties are unset which means no limits are set. Assuming your application is deployed as tempo-worker and you want to set your CPU limit to 500m and memory limit to 1Gi:
juju config tempo-worker cpu_limit=500m
juju config tempo-worker memory_limit=1Gi
Same configuration properties are available in the tempo-coordinator charm, assuming your coordinator is called tempo:
juju config tempo cpu_limit=500m
juju config tempo memory_limit=1Gi
See Tempo HA resource consumption to estimate values you might need in your setup. For an explanation of resource limits, see Resource Management for Pods and Containers.