JS non-encoding special character issue on Qualtrics

The issue is we are triggering a JSON Workflow event in the following way:

fetch('https://qualtrics-url.com', {
method: 'POST',
headers: {
'Accept': 'application/json',
'Content-Type': 'application/json',
'X-API-Token': 'xxx'
},
body: JSON.stringify({var: 'h=fi<una'})
}).then(res => res.json())
.then(res => console.log(res));

From there we send email using the var we passed above.
However, in the email we receive, h=fi only, and not the rest of the part.
If I do encodeURIComponent, then I receive the full string in encoded format in email, but I want the non-encoded version.
If I do encoded, the output will be h%3Dfi%3Cuna instead which also isn’t correct.

Any workaround with such issue?
I encountered this using JS on Qualtrics.