SHOULD repent, turn to, do works - optional ????

What does SHOULD mean today ?
https://langeek.co/en/grammar/course/699/should-vs-must
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KJV Acts 26:20 then to the Gentiles, that they should repent and turn to God, and do works meet for repentance.
SHOULD - repent
SHOULD - turn to God
SHOULD - do works...
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The Greek does not include SHOULD
How did KJV & many others get it so wrong ?
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1611 orig KJV :- ALSO writes SHOULD.
I suspect SHOULD was more of a MUST than optional back then

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