Is it safe to pass client_id and secret in base64 to the application?

Question

Information Security

There is WP with a custom endpoint in the API. The application logs in via oAuth 2, receives a token and works with data, sending a token to the header of each request.
I have doubts about how safe it is to send in a request for a token id and secret in the header, in base64?
The application is on ionic and in theory, anyone can sniff what it sends and get my data to connect to the API.
I still don’t know what it threatens, but a person can use my API like that, but I don’t want it.
Login is done like here - https://wp-oauth.com/kb/user-credentials/
API on domain with SSL

Answer 1

base64 is not an information security tool

Answer 2

base64 is not an information security tool

Anyone can sniff, but it will not be possible to decrypt, for this they actually encrypt./blockquote>
Colleagues, you have confused me. Let's get back to a specific case, there is an application and there is an oAuth 2 server where the login goes through sending a combination of client id and secret to base 64 in the header. What threatens me?