No. You are not medical provider and should not make medical decisions on behalf of others.
Your client has to create request the product through the portal and fill out the medical intake form. Then a clinician can prescribe when appropriate.
This is a protection, not a limitation. Ordering on someone else's behalf may be considered making medical decisions for them without a license.
You can educate and provide access toward the products that fit their interests, but the request itself has to come from the client.