While it's unclear if you're looking for a way to send messages without a credit card or a tool to generate "fake" text image, there are several ways to do both.
Many services allow you to send real SMS or make calls over Wi-Fi without ever asking for payment information. no credit card
Allows unlimited texting to the U.S. and Canada and provides multiple phone numbers within one account. Business Texting Trials While it's unclear if you're looking for a
A popular choice that provides a free U.S. or Canadian phone number for unlimited texting and calling over Wi-Fi. no credit card