This error message indicates that there is a size mismatch when trying to concatenate two tensors. Specifically, the target size is [10, 3072], but the tensor sizes are [20, 3072]. This suggests that the dimensions of the two tensors being concatenated do not match.
To fix this issue, you may need to check the shape of the tensors and ensure that they have compatible dimensions before concatenating them. One approach could be to resize one or both tensors to match the desired target size before concatenating them. Another approach could be to modify the code that generates these tensors so that they have matching shapes from the start.