If you’re wanting to convert either multi-line selections, or a find / regex pattern to uppercase or lowercase

Convert a find / regex pattern Link to heading

Search for the pattern you want to convert

Find replace screenshot

Make sure to wrap the regex in ().

In the replace field, enter \L$1 for lowercase, or \U$1 for uppercase.

Convert select text to upper, lower, title, or camel case Link to heading

Select the text you want to convert, open the command pallet (Windows: CTRL + SHIFT + p | Mac: CMD + SHIFT + p), search for transform and select the text transform you need. Ezpz.

Transform screenshot