How to prescribe the prepared text in the description of a specific type of tasks?

Previously, it was team-managed (there you could easily write a template in the "description" field). Now the project type is company-managed. Can you please tell me where can I change this field?

See my earlier comment about changing the Field Configuration.  :-)

i saw your comment and found the fields configuration. But I did not find a way to enter the text that would be displayed when creating a task of the "bug" type.

Ah, sorry, I was thinking of the description associated with the field. This is a little trickier for Company-managed projects because the Description field is shared across all of those types of projects. So if you put in a Default Value (which is where you would put it), then it will affect ALL Company-managed projects. 

So, what we do is create a new custom field of paragraph type. Then you can modify the context for the field to be used by that project (Settings > Issues > Custom Fields, then search for your new field and click the 3 dots menu and select Contexts and default value).

There you can put your prepared text in the Default value for the field.

Also be sure to put the new custom field on the create screen (or form) for that project. You could even hide the Description field in the create screen for that project if you want to avoid confusion. Just be sure that you leave the Description field on the Edit screen. (You might even want to hide the new custom field on the Edit screen so that only the Description field gets updated moving forward. )

Finally, you can create an Automation rule to copy the value from the new custom field to the Description field if you like. This would be done with an Issue Create trigger and a condition where the custom field is not empty. 

thanks i will try to do that

I could not get. It seems that I did everything according to the instructions, at the step of adding the context I wrote my own text, but it was displayed as a description to the "description". And I need the text to be in the "description" field. In addition, I realized that even if it is possible, still unlike a team-driven project, you cannot format the test. There is no editor to insert titles, color, icons, etc. I wanted to do what I had in a team-driven project (see screenshot 2). But it didn't work out that way (see screenshot 1).

You don’t put it in the description, it needs to go in the default value.

Получилось, спасибо!

Не могли бы в подсказать, как сделать это поле форматируемым? В поле "абзац" можно прописать только текст и эмодзи. Мне нужно чтобы можно было определить цвет, а главное выбрать размер заголовка. 
В проекте управляемым командой есть редактор, где все это можно сделать (см. скрин 3), а в управляемом компанией почему-то нельзя.

Если это невозможно, быть может вы подскажите какой-то сторонний плагин для ведения баг репортов, где можно создавать такие шаблоны, с возможностью форматирования?

Большой! Я рад, что это сработало.

Вам нужно изменить средство визуализации для настраиваемого поля в конфигурации поля.
Перейдите в «Настройки» > «Проблемы» > «Конфигурации полей».
Затем найдите конфигурацию поля, используемую в этом проекте.
Выберите его, а затем найдите настраиваемое поле.
Затем щелкните ссылку Рендереры.
Наконец, измените рендерер на Wiki Sytyle Renderer.

Thank you. I did it!