I want to add files with sizes larger than 2GB to Attachments.

[kimjeongmin]

I want to add a size file of 10GB to the Attachments item in ISSUE.

JIRA cannot add files of size 2GB or more, what should I do?

[Iago Docando]

I will advice you against doing that. 

Nic Brought offers a bit more insight about that in this topic:

https://community.atlassian.com/t5/Jira-Software-questions/how-to-increase-the-max-attached-file-size-larger-than-2GB/qaq-p/1533152