I want to remove the Icon in the red frame. What do I have to do Have an example of an angular 5 code?

Hello,
It seems that this question was already discussed in the following threads: https://www.webdatarocks.com/question/how-can-i-add-custom-tool-bar-and-custom-tool-bar-buttons/ , https://www.webdatarocks.com/question/adding-custom-tab-to-toolbar/.
Regards,
WebDataRocks Team

thank