You can connect Zapier to Webflow forms and save text submitted to many different places including Google Sheets and the Webflow CMS. When text is saved to the Webflow CMS it can then be displayed on a Webflow page. (The textbox would need to be in a form which is submitted by the website visitor).
The first 20 minutes of this video describe the process of setting this up in detail.
The below page has more information about how to do this.