Terms and Conditions are an agreement between you and your supplier/vendor. This agreement may specify the terms of delivery and payment, credit periods and payment types, the risk of loss etc.
Open the left-side menu, go to Configuration -> Basic settings and open the Purchase Orders tab, then you may add your documents in any desirable format - MS Word file, MS Excel table, PDF document or a simple image.
Don't forget to press the Update button to save changes!
You are able to add several documents and choose the one to be attached while creating the PO. This could be helpful if you have different terms for a specific supplier or if the payment terms may differ from one supplier to another.
The Order T&C will be attached to your PO on Precoro itself and also to your letters (if you are sending your POs from Precoro).