not able to add a second Technicians

not able to add a second Technicians

ServiceDesk Plus Standard edition - I am not able to add a second Technicians.
If I do "Change a Technicians" choose a name and try "Save" I got error "Your license type does not allow you to add more than 1 technician."
But if I look into this page https://www.manageengine.com/products/service-desk/sdp-editions.html there is information about up to 5 Technicians.
Thank you for your help.

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