Can I upgrade P9981 to OS10?

I have 9981 and wanted to test OS10 app (.bar) so i borrowed P9981 from a friend, it turned out it runs OS7 not 10

googled a little seems not possible to upgrade to OS10

any workaround to upgrade it to OS10 to test this app? or i just get 9982/3 to test it out?

There's no way to upgrade pre-BB10 phones to BB10.