writing a code for creating similarity scores for the character string of all possible pairwise comparison by group -- 2

I am looking for a freelancer to help me write a code for creating similarity scores for the character strings of all possible pairwise comparisons by group. The ideal freelancer will be experienced in using R as the programming language for the code. I am open to suggestions for the similarity scoring method, as I trust the expertise of the freelancer selected. The size of the character strings to be compared is expected to be large, exceeding 1,000 characters. If you have the skills and experience needed to complete this project, I look forward to hearing from you.