How to customize toolbar buttons on markdown toolbar

I’m using react-tinacms-editor markdown component in my form. Below is my form field configuration.
label: ‘Emergency Message’,
name: ‘message’,
component: ‘markdown’,

With this configuration, I see only bold and italic buttons on the markdown toolbar but I want to add “anchor hyperlink”, “heading 1” buttons to the toolbar.

How can I achieve this?

Thanks in advance.