Calling tx/:txid and /block-height/:height "in sync" based on bitcoind zmq notifications

I'm running regtest scenarios where my code is calling my local esplora backend REST api based on bitcoind zmq notifications with `zmqpubhashtx` and `zmqpubhashblock`. My issue is that I call these two endpoints (`tx/:txid` and `/block-height/:height`) before esplora backend actually index them, which is causing errors:
```
INFO - handle GET /tx/8332bc9fe058113cae99b31f5472a71a757cc3cf6710ba7b2c3ca0586219333f
WARN - HttpError(404, "Transaction not found")
INFO - handle GET /block-height/106
WARN - HttpError(404, "Block not found")
```

Is there a way to call this endpoints only when these resources are available ?