Passing null to parameter #1 ($string) is deprecated

Problem/Motivation

After enabling the animatecss_block module placing any new block from block_layout was sending the below error.

Object { message: '\nAn AJAX HTTP error occurred.\nHTTP Result Code: 200\nDebugging information follows.\nPath: /admin/structure/block/add/entity_view%3Anode/mtcbtheme_bs4?region=drawer_top\nStatusText: parsererror\nResponseText: Deprecated: strtr(): Passing null to parameter #1 ($string) of type string is deprecated in /app/docroot/modules/contrib/animatecss_block/src/Service/AnimateCssBlockHelperService.php on line 248\n[{"command":"settings","settings":{"ajaxPageState":{"theme":"vartheme_claro","theme_token":"aUVtYr7GmL5_ALCKifq0yPq-GSLeEKPAdQWjPDSSF28","libraries":"eJx9U1GWpCAMvBDqGfYkvoBpzWskPhLdnT39RlSmnd6ZHyFVRSRFAsNMqVfm6CF359pqRnTwLdVOvGGmpJj0LiurVDEFTg4SzaAYRHofOTy7E2hK9EqvVLkwpGbAzXka-4UW7K6NO3IMeV0gtkeKd6gtt3JhYsHUHUvr8XEhp_aITrCP5C-p3caFCJkvZYKtUfCG8uOBWBOUyEDz4o-uED-JC2kipaf8LDn9MlGuqSEobVhO3_DAMcIieAOHzItfVc3uV3iGMFHCJsF814uayXKDrLqIE8KA-R3PKAsnsQvdOOsCpbAXcFhjTOI8Q6S_6Oz50Irdv7VATBtlTrM1Tk9psLPK-cr2X9KZRbsHVXSETlCV0ii9ZvioZb2CTibOGlat7Bk74UAQ-xkHgr48T_cOtTqhuab8tH4pX_d1FlACLPirtJqy2vn9TTPHToMB66…', name: "AjaxError", stack: "@https://mtcbenin.lndo.site/core/misc/ajax.js?v=10.3.3:196:32\n@https://mtcbenin.lndo.site/core/misc/ajax.js?v=10.3.3:1921:3\n" }

Steps to reproduce

- Enable the module.
- From Block layout page try to place a new block to any region

Proposed resolution

i am not expert but, after reading another similar issue on paragraph i try imitating a patch they provided here. i attach my imitated patch here

Remaining tasks

- Maintainer confirm it's the correct solution
- Test and review for the patch