How to enable "Submit to approve" for all (regular) users?

How to enable "Submit to approve" for all (regular) users?

Hi!
We recently introduced Zoho Invoice on a slightly bigger scale in our team and added the regular approval layer.

In our daily work we were hitting a wall with this since apparently not every "regular" user can submit invoices but only in cases if he is either the creator of the invoice or an Admin (with approval rights).


How does approval need to be set up to enable regular users to submit any invoice for approval? Couldn't find a setting either on permission level for the role nor the approval config page.

Background:
We have a team of eight account managers which create and manage the invoices. Following a two-men-approach the invoices get checked by another/second account manager in the team before submitted for approval to the two supervisors.

Thanks!