What is the ruling on providing an agency? And is there any prohibition in it?

If the questioner intends to deposit money into a savings account at a specific banking agency, then the ruling on this transaction is a branch of the ruling on the banking agency itself. If it is an Islamic banking agency, and the method of investing savings accounts is compliant with Sharia standards, then the transaction is permissible. However, if it is a commercial interest-based agency, then the transaction is forbidden.