SLM mode of Containers are set per hosting plan in PBAS.

For instance, the Container #12 belongs to the subscription #34 that is based on the hosting plan #56.

To change SLM mode of the Container, please go Top > Billing Director > Product Manager > Hosting Plans > #56 > Container Properties tab, set the desired SLM mode and upgrade the subscription #34 to the latest hosting plan version.

More information on changing SLM modes in hosting plans can be found in Provider's Guide:

Adjusting Container General Properties for Virtuozzo Container and Virtual Plesk Node Hosting Plans