Is it possible to authentification on JIRA API without server between client and Jira

unknown

I built a client application (angular) that allow to my team to create jira issue.

The user has to login with their jira credential (user and pw) on my app.
 
To post a issue on JIRA API I'm using basic auth on the request  header :
"Authorization: Basic XXXXXXXXX"

It worked well until we update JIRA and now basic auth not working anymore. 

What is the best solution to make my app work again ?

Should I implement OAuth but I need a server to manage the Jira OAuth logic or is there any other solution keep a simple client app to communicate with JIRA API ?

unknown

So, I juste use a proxy on my angular app (client) to be able to keep going the development. For long term solution I'm gonna use a server backend as a proxy to make requests to the JIRA API and then relay the response to my client and add CORS on requests.