Custom Form Type templating

[xPaw]

Hello,

 

I added form type and now i want add template for this field.. but when i add this in services.yml

twig:
	form_themes:
		- '%kernel.project_dir%/modules/mymodule/src/View/myfieldview.html.twig'

after that, when i debug twig from command line this theme is registered but not work 😕

When i add this same code to app/config/config.yml in twig section all work fine

 

Anyone know how to improve this?

Regards