Hi @Amit Rawat
Welcome to Microsoft Q&A! Thanks for posting the question.
The new designer is rolled out for a few percentage of users. If you want to revert back to the old designer then as a workaround you can use the below link, but this only works for consumption. For standard logic apps, it is always using the new designer.
https://portal.azure.com/?feature.experimentation=false&feature.experimentationflights=v2cf
Please 'Accept as answer' and ‘Upvote’ if it helped so that it can help others in the community looking for help on similar topics.