I think i found solution
model = nn.Linear(10, 2)
optimizer = optim.SGD(model.parameters(), lr=1e-3)
steps = 10

scheduler=CosineAnnealingLR(optimizer, T_max=15*2240//2, eta_min=0, last_epoch=-1, 
                            verbose=False)
lrs=[]
for epoch in range(15):
    for idx in range(2240):
        if epoch>15//2:
            
            scheduler.step()
            #print(scheduler.get_last_lr()[-1])
        lrs.append(scheduler.get_last_lr()[-1])