Remove Electra Jailbreak

i want to upgrade my ios on an iphone x and get rid of the electra jailbreak.

when i run the unjailbreak.sh from putty i get the following

unjailbreak.sh: line 7: syntax error near unexpected token `newline’
unjailbreak.sh:

any ideas on where to go from here? I tried just updating the ios, but it failed so im guessing i need to have the jb removed first, but not sure

any help is appreciated