Expresses the concept of not only doing verb but also something more; 'not limited to', 'not only... but also'.
Long explanation:
The grammar point Verbる にとどまらず~も is used to express that an action or situation is not limited to just the verb but also includes something more. It can be translated as 'not only... but also', 'not just', 'not merely', 'beyond' in English. The verb is in its dictionary form.