Why is it invalid?

Hi, I tried to set up exemption for paypal website using walled-garden using suggested command lines in kiwi as below:
/ ip hotspot walled-garden add dst-host=:^www\.paypal\.com$ dst-port=443 action=allow
/ ip hotspot walled-garden add dst-host=:^content\.paypalobjects\.com$ dst-port=443 action=allow
It appears that something is wrong when I typed the backwards slashes as they were highlighted. Also when pressing enter key error message appeared:
expected end of command (line 1 column 46)
So, what is wrong here?

The syntax on the dst-host command looks very strange…

dst-host=:^www\.paypal\.com$
dst-host=:^content\.paypalobjects\.com$

What does the “:^” mean, and why all the backslashes?

I’d imagine this would work:
dst-host=“www.paypal.com/$”
dst-host=“content.paypalobjects.com/$

If it is wrong, it should be corrected in wiki.mikotik.com as many people would rely on it for assistance. I need my walled-garden exemption to work in order to do automatic payment set up in userman.