The HTML field toolbar editor options render differently in the native platform and may not show on the Service Portal. The HTML field toolbar (which is rendered via TinyMCE) is inherently different on Service Portal compared to the native platform.
Navigate to .
For more information, see the product documentation topic Order guides.
Select the New Hire order guide.
Add a variable - sn_test of type HTML.
Open the order guide by clicking the Try it button.
The sn_test HTML field appears on the form.
Check the same form in Service Portal.
The sn_test HTML field is displayed.
Modify the glide.ui.html.editor.v4.toolbar.line1 system property to add the "strikethrough" editing icon in the TinyMCE editing toolbar and save it.
Check the New Hire order guide.
Note that it shows the Strikethrough icon on the toolbar in the instance but not on Service Portal.
There is no known workaround at this time. This is being considered as an enhancement request.