Transaction Approval Workflow Configuration

a) How? to configure approval workflows for manual and imported invoices by role-based.
b) The following functionalities needs to be explored:
i. Requesting additional information during approval.
ii. Delegation of approval
iii. Multiple approvals on same transaction.
iv. Transferring approval ownership to another user.

We operate in the airways industry and are exploring the setup of a serial approval workflow.

We have already tested both user-based and role-based approval configurations.

Could you please clarify the recommended approach for implementing a serial (sequential) approval process, and how it can be best configured or optimized in our environment? We are currently in the test phase, we've not gone live yet