Which issue tracker to choose?

Question

Helpdesk

Hello.
I'm looking for a paid/free issue tracker/service desk with the following functionality:
- a client portal for initiating requests (perhaps even with personal accounts);
- business processes customizable from scratch for each type of applications;
- customizable SLA at each stage of the application;
- flexible reporting system that can be collected from any atomic elements of the system (report on performers with SLA at each stage of the application business process, for example, to see who has what weaknesses);
- dashboards for these reports/views;
- integration with mail (outlook, gmail and other web services) - receiving letters about status changes, etc.;
- support in any form for the implementation of the system and basic settings;
- Russian localization is desirable.
Wishlist:
- maintaining a knowledge base and the ability to attach articles to solutions;
- creation of response templates with parsing of full name and so on. client data to insert;
- integration with telegrams, possibly a bot on request;
- mobile application/interface for making calls and their fulfillment/tracking.

Answer 1

see https://www.redmine.org/

Answer 2

https://otrs.com/