This action would add [2] total shards, but this cluster currently has [2000]/[2000] maximum shards open;

Invalid Bulk items: operation[0]: index returned 400 _index: transactions-es-nfnxl530-20200911 _type: _doc _id: 909090892 _version: 0 error: Type: validation_exception Reason: Validation Failed: 1: this action would add [2] total shards, but this cluster currently has [2000]/[2000] maximum shards open;

Any help is appreciated

You have too many shards in your cluster and should rethink how you index data in order to reduce this. You can increase the limit, but having lots of small shards is very inefficient and will eventually cause problems which is why this limit was introduced.

I would recommend reading this blog post for more details. This post may also be helpful.