I'm trying to create a toolbar with a dropdown menu in my grid, similar to the demo shown here: https://demos.telerik.com/aspnet-core/grid/toolbar-template.

I can not find any information on doing it with tag helpers.

Hi Johannes,

At present, the toolbar template is not available with the TagHelpers of the Telerik UI Grid. I encourage you to vote for this item in our feedback portal so that it gains popularity and gets implemented in any of the upcoming versions. 

As a temporary workaround, you can plug the whole template inside a bottom and achieve the same functionality:

<toolbar>
    <toolbar-button template="myTemplate"></toolbar-button>
</toolbar>

function myTemplate(e) {
    return "<button id='1'>btn 1</button> <button id='2'>btn 2</button>";
}

I hope you find this helpful.

Best regards,
Tsvetomir
Progress Telerik