Create an estimate through Excel with the API

Extensibility
18

Just a general tip for pasting code as sometimes non-visible characters or tabs/spaces can be an issue so screenshot is often no good;

Use code tags (3 backticks before and after the code) like so.

```
Code goes here
on the next line etc
```

Gives;

Code goes here
    on the next line etc

Or you could use https://www.pastebin.com/ if the code is particularly long and detailed.