Can't change copyright

I had SD installed and code snippet worked fine to change copyright. after I changed themes and then changed back, the snippet stopped working and now I cannot get rid of the default copyright. I tried all the snippet combinations but here is the last one I used. Cannot figure out why it is not working.

function dt_remove_default_footer() {
remove_action( ‘dt_footer_copyright’, ‘dt_footer_copyright_default’, 10 );
add_action( ‘dt_footer_copyright’, ‘_my_dt_footer_copyright_text’, 10 );
}
function _my_dt_footer_copyright_text(){
echo ‘Copyright 2017 – 2018 ProShark © All rights reserved’;
}

I will resend temp login creds.