As a tech partner, and soon as an agency partner, you can go to the Agency Partners tab to find the button to Request Partnerships. Once you click that button you will find the page as shown above.
Currently, all agency partners are shown by their agency type. If a partner fits in more than one category they will show in each but you only need to request them in one category to match with them on all.
Select one or more partners to connect with and scroll back to the top of the page to click "Add" to instantly send the partnership request(s) to all selected partners.\
Inviting a partner
If you are looking for a partner who is not yet on Partner Partner you can go to the main Agency Partners tab and click the Invite Partner button or copy the link for a custom email approach. The Invite Partner button will send a quick email to the address you provide asking them to join Partner Partner from you.