To upgrade to 10.0.40 you would need at least LAC 6.20.1. With that being said, LAC 6.21.1 has been released with hotfixes and this is the version Elelqtus recommends. Lasernet FO Connector Compatibility - Knowledgebase / Lasernet FO Connector / Lasernet FO Connector Compatibility - Formpipe Support Portal 
You can get more information regarding the LAC 6.21.1 here.

Furthermore, there were big changes that have been introduced with LAC 6.20 and LAC 6.21 and we recommend that anyone on your team who is responsible for supporting and managing Lasernet to be familiar with the changes. Below are some links to reference: 

Here’s a link directly to LAC 6.21.1 package: https://prsupportdownloads.blob.core.windows.net/fo-connector/6.21.1/LAC365FO_Version_6.21.1.2407103_Update64.zip

6.20 New Features and Fixes: https://support.formpipe.com/news/posts/lasernet-fo-connecor-620-new-features-and-fixes
6.21 New Features and Fixes: https://support.formpipe.com/news/posts/lasernet-fo-connector-621-new-features-and-fixes

You will also need to download separately Default Configurations. I have added the link to access the installer Package below; 
https://prsupportdownloads.blob.core.windows.net/fo-connector/6.21.1/Default%20configurations.zip

Refer to the video below for guidance on how to import the Default Configuration. 
How to Import the Default Configuration for Dynamics | Lasernet for Dynamics 365 - YouTube  


If you require further assistance, please create a ticket and an Eleqtus agent will address any questions!