Here,s the regex answer.
Explanation
/
(?<=start text\s).*(?=\send text)
/
Positive Lookbehind (?<=start text\s)
Assert that the Regex below matches
start text matches the characters start text literally (case sensitive)
\s matches any whitespace character (equal to [\r\n\t\f\v ])
.* matches any character (except for line terminators)
* Quantifier — Matches between zero and unlimited times, as many times as possible, giving back as needed (greedy)
Positive Lookahead (?=\send text)
Assert that the Regex below matches
\s matches any whitespace character (equal to [\r\n\t\f\v ])
end text matches the characters end text literally (case sensitive)
Cheers