Following this post, I am trying to access all transactions within the #630873 block in the bitcoin blockchain.

import requestsr = requests.get('https://blockchain.info/block-height/630873?format=json')
data = r.json()

When inspecting the (0-indexed) 4th transaction within this block (via data['blocks'][0]['tx'][4]['out']), I get this:

[{'n': 0,'script': '0014d0aba2c93bac0fcafafe43f2ad39d664ba51910d','spent': False,'tx_index': 0,'type': 0,'value': 19571491},{'addr': '1A7tWftaGHohhGcJMVkkm4zAYnF53KjRnU','n': 1,'script': '76a9146406a0a47d4ed716f6ddf2eeca20c725932763f188ac','spending_outpoints': [{'n': 0, 'tx_index': 0}],'spent': True,'tx_index': 0,'type': 0,'value': 3928145371}]

Only the addr of the second recipient of this transaction is included. On the blockchain.com website this transaction looks like:

The bc1q6z469jfm4s8u47h7g0e26wwkvja9rygdqpeykd address is visible there. How to access it through the API?

The unaccessible address has BECH32 format, while the accessible one has BASE58 (which information I get by clicking on the address on the website). Those transactions which I was able to retrieve the reciepient address, had BASE58 format.

Link to the block I am talking about..

The Blochchain.com API does not fully support bech32 addresses yet.

So you could use another provider such as Blockstream or Blockchair.

Or you can also derive the addresses from the P2WPKH script. For example using BitcoinLib (Disclaimer: my library):

from bitcoinlib.transactions import script_deserialize
from bitcoinlib.keys import Addresslocking_script = '0014d0aba2c93bac0fcafafe43f2ad39d664ba51910d'
scr = script_deserialize(locking_script)
a = Address(hashed_data=scr['hashes'][0], script_type=scr['script_type'])
print(a.address)