UnicodeEncodeError: 'latin-1' codec can't encode character '\u2082' in position 289702: Body ('₂') is not valid Latin-1.

Nobody has claimed this yet.

I'm trying to POST an XML file which has elements like `SpO₂`. Request fails with following error:

> UnicodeEncodeError: 'latin-1' codec can't encode character '\u2082' in position 289702: Body ('₂') is not valid Latin-1. Use body.encode('utf-8') if you want to send it encoded in UTF-8.

Traceback (most recent call last):
File "/home/wlad/.venvs/ehrbase/lib/python3.9/site-packages/RequestsLibrary/utils.py", line 138, in decorator
return func(*args, **kwargs)
File "/home/wlad/.venvs/ehrbase/lib/python3.9/site-packages/RequestsLibrary/RequestsOnSessionKeywords.py", line 60, in post_on_session
response = self._common_request("post", session, url,
File "/home/wlad/.venvs/ehrbase/lib/python3.9/site-packages/RequestsLibrary/RequestsKeywords.py", line 37, in _common_request
resp = method_function(
File "/home/wlad/.venvs/ehrbase/lib/python3.9/site-packages/requests/sessions.py", line 590, in post
return self.request('POST', url, data=data, json=json, **kwargs)
File "/home/wlad/.venvs/ehrbase/lib/python3.9/site-packages/requests/sessions.py", line 542, in request
resp = self.send(prep, **send_kwargs)
File "/home/wlad/.venvs/ehrbase/lib/python3.9/site-packages/requests/sessions.py", line 655, in send
r = adapter.send(request, **kwargs)
File "/home/wlad/.venvs/ehrbase/lib/python3.9/site-packages/requests/adapters.py", line 439, in send
resp = conn.urlopen(
File "/home/wlad/.venvs/ehrbase/lib/python3.9/site-packages/urllib3/connectionpool.py", line 699, in urlopen
httplib_response = self._make_request(
File "/home/wlad/.venvs/ehrbase/lib/python3.9/site-packages/urllib3/connectionpool.py", line 394, in _make_request
conn.request(method, url, **httplib_request_kw)
File "/home/wlad/.venvs/ehrbase/lib/python3.9/site-packages/urllib3/connection.py", line 234, in request
super(HTTPConnection, self).request(method, url, body=body, headers=headers)
File "/usr/lib/python3.9/http/client.py", line 1257, in request
self._send_request(method, url, body, headers, encode_chunked)
File "/usr/lib/python3.9/http/client.py", line 1302, in _send_request
body = _encode(body, 'body')
File "/usr/lib/python3.9/http/client.py", line 164, in _encode
raise UnicodeEncodeError(

Here is how I send the request (${file} is loaded via `Get File` keyword)

```robotframework
${resp}= POST On Session ${SUT} /definition/template/adl1.4 expected_status=anything
... data=${file} headers=${headers}
```

If I remove `₂` from the payload the request succeeds

What am I missing? The XML files actually starts with
```xml

```

Start with RequestsLibrary/RequestsOnSessionKeywords.py at post_on_session, then follow _common_request in RequestsKeywords.py into the requests call shown in the traceback. Reproduce the POST using the XML containing “₂” and inspect how the loaded body is passed to the HTTP client. Done means the expected encoding behavior is established and the issue is either fixed or clearly identified as belonging upstream.

Written by the indexing model from the issue text.