The feature is still there. Like many things, though, the access to it
First, if you don't have the Developer tab showing in the Ribbon, go
to Office button > Word Options and check the box for "Show Developer
tab in the Ribbon".
On the Developer tab, in the Controls group, click the Legacy Tools
button (the fourth one in the second row). The check box form field
button is the second item in the menu. You'll also need the Protect
Document button, near the right end of the Developer tab.
Microsoft Word MVP
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