How to add a piece of uneditable text?

You can use a component's label property to set the text displayed with the component. Multiple component types support setting the labelPosition so that you can change the position of the label with respect to the component. Alternatively, you can set the description property to display text a bit more subtle, under the component.

If this does not meet your demands, you can use an HtmlElement component. For example:

h           = component.HtmlElement("Title", form);
h.content   = "Page title";
h.tag       = "h1";

h = component.HtmlElement("Title", form)
h.content = "Page title"
h.tag = "h1"

The resulting title is:

HtmlElement component example