Text on the image versus text in the fields
Most "Pinterest fonts" people admire are on the Pin image: big script headlines, serif titles, handwriting. That text is part of the picture and is made in a design tool before upload. This generator cannot change it.
What it can change is the text in Pinterest's fields: your display name, your 500-character about text, board names and Pin descriptions. Those accept Unicode, so a styled word there shows as styled everywhere.
Keep the searchable words plain
Pinterest finds Pins through the words in titles, descriptions and boards. A styled word is a string of symbols to search, so it stops working as a keyword. That makes Pinterest the platform where styled text costs the most.
A safe pattern: plain keywords in Pin titles and descriptions, a styled touch in your profile name or about text, where branding matters more than search.