Hello there !!! This is where people usually get confused.
First of all, please go through regular installation process as below:
1. Upload the plugin files to the /wp-content/plugins/text-united-translation
directory, or install the TextUnited plugin through the WordPress plugins screen directly.
1. Activate the plugin through the ‘Plugins’ screen in WordPress.
1. Use the TextUnited Plugin Section in side panel – Enter your credentials to connect to TextUnited API and to configure the plugin.
**Demo – Multilanguage WordPress Translator Plugin**
[youtube https://www.youtube.com/watch?v=xO5kkBPw_IU%5D
This video will help you a lot to understand how to install the TextUnited wordpress translation plugin.
Finally, as you mentioned you deactivated and then activated the plugin, you have to log on to the [TextUnited account](https://www.textunited.com/my/extras/api/) to get the company ID and API key.
Use your login details that you registered with TextUnited first time.
Hope this will help you connect to the TextUnited API.