AssignMessage Set Path won't work

[VK]

Here my AssignMessage:

<AssignMessage continueOnError="false" enabled="true" name="Assign-Message-1">
    <DisplayName>Assign Message-1</DisplayName>
    <Properties/>
    <Set>
        <Path>/get</Path>
    </Set>
    <IgnoreUnresolvedVariables>true</IgnoreUnresolvedVariables>
    <AssignTo createNew="false" transport="http" type="request"/>
</AssignMessage>

and it won't set path.
The main idea here: I have target endpoint: https://httpbin.org
and I need at runtime add path to it /get or /post,
here in my example I have only /get just for simplicity.

Could someone please help figure out how to set path in AssignMessage?

Here you can find all apiproxy xml files (apiproxy.1.zip).