Please check the Claris™ Engineering Blog with a lot of interesting articles. Just recently they added one for plugin installation for FileMaker Server 19.3 with Data API:

• Enabling plug-ins for FileMaker Data API in FileMaker Server (June 24, 2021)
• Claris FileMaker 19.3.1 Platform bug fixes (June 23, 2021)
• FileMaker Platform performance improvements on Apple silicon (June 23, 2021)
• Verifying SSL for FileMaker Server (May 6, 2021)
• Uploading large databases to FileMaker Cloud using the FileMaker Admin API (March 18, 2021)
• Working around FileMaker Data API authorization timeouts (March 4, 2021)
• Modifying web publishing behavior for FileMaker Server (February, 8, 2021)
• Upgrading to FileMaker Server 19.2.1 (January 26, 2021)
• PHP bundling deprecation and removal from FileMaker Server (January 8, 2021)
• HTTP/2 support in FileMaker Server (December 22, 2020)
• Understanding FileMaker database memory caches (December 10, 2020)
• Migration options for FileMaker Cloud for AWS (November 11, 2020)
• Performance, stability, and reliability improvements in Claris FileMaker Server 19.1.2 (October 28, 2020)
• Considerations for configuring SSL certificates for FileMaker Server (October 20, 2020)
• Best Practices for Database Administration (September 25, 2020)
• Configuring Microsoft Azure Active Directory for authenticating FileMaker Cloud users (September 18, 2020)
• Authenticating Claris ID and Granting Access to FileMaker Admin API and Data API (August 27, 2020)
• Updated: Understanding Your Claris FileMaker Cloud Instance (January 19, 2021)
• Best Practices for Upgrading to FileMaker Server 19 (July 27, 2020)
• Top Tips: Optimizing Performance of FileMaker WebDirect in the Cloud (July 1, 2020)
• Top Tips: Optimizing Performance of FileMaker Custom Apps in the Cloud (June 5, 2020)