Error in score_mutant.ipynb

[MichaelAbel1]

structure_sequence_offset = [i + 3 for i in structure_sequence]
TypeError: can only concatenate str (not "int") to str

Is the following correct？ and if so what does it have to do with +3, isn't this the result of clustering the embedding representation of each residue？

structure_sequence_offset = [i + 3 for i in structure_sequence['2048']['GRB2_HUMAN_Faure_2021.pdb']['struct']]