error in dreambooth.ipynb (Unit 3)

[phananh03x]

I tried to run the 'notebook_launcher' function and got error:

/usr/local/lib/python3.8/dist-packages/bitsandbytes/functional.py in optimizer_update_8bit_blockwise(optimizer_name, g, p, state1, state2, beta1, beta2, eps, step, lr, qmap1, qmap2, absmax1, absmax2, weight_decay, gnorm_scale, skip_zeros) 950 951 if g.dtype == torch.float32 and state1.dtype == torch.uint8: --> 952 str2optimizer8bit_blockwise[optimizer_name][0]( 953 get_ptr(p), 954 get_ptr(g),

NameError: name 'str2optimizer8bit_blockwise' is not defined