Base64 version throwing error

[vidoardes]

When I use the Base 64 command as below:

adb shell am broadcast -a ADB_INPUT_B64 --es msg `echo '你好嗎? Hello?' | base64`

I get the error:

Check the spelling of the name, or if a path was included, verify that the path is correct and try again.
At line:1 char:66
+ ... b shell am broadcast -a ADB_INPUT_B64 --es msg echo 'Hello?' | base64
+                                                                    ~~~~~~
    + CategoryInfo          : ObjectNotFound: (base64:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException```