Short answer: no

A single booking is paid in full either with your subscription or with credits. It is not possible to cover part of one activity with the subscription and the rest with credits.

What you can do instead

If an activity costs more than your subscription covers, for example more than 3 credits on S or more than 5 credits on M, you can book it entirely with credits.

A booking paid with credits does not use your subscription. This means that on the same day you can still use your subscription for another activity within its limit.

Where the credits come from

You can use credits you have bought in the app, or credits you received as a reward. If your monthly company credits were converted into a subscription, they are no longer available as credits, so for activities above the subscription limit you will need to buy credits.

Purchased credits do not expire, so you can keep them for the activities you book less often.