How to get multiline contents of RegExp?

Question

JavaScript

There is a regular expression RegExp('(.*?)<' + '/tag>', 'gim').
Returns only if there is one line inside tag. If there is a carry at the beginning or at the end, then there is no match. Is it possible to apply the "m" flag to the search content?

Answer 1

should be something like
RegExp('<tag>(.+?)</tag>', 'gim')

Answer 2

<tag>([.\n]+?)</tag>