Do all plants throw male flowers from over-maturation? I know it can happen, I've seen pictures and some of the plants I've grown outdoors have thrown a couple random seeds despite being nowhere near a male to my knowledge (though never seen a male flower so I generally assumed it could be a neighbors male responsible).Top the plant for multiple colas.
Then spray a branch.
But if you only have 1 plant you'll prolly need to clone it to get seeds.
Or let your plant go for s very long time.