We can use God’s name, Yahweh, if we would like. The Old Testament uses it lots of times (in most English Bibles it’s there whenever the Old Testament says Lᴏʀᴅ or Gᴏᴅ [in small caps]).1
If we choose not to use God’s name, that’s also fine. The New Testament, for example, doesn’t use it once.2
1. See ‘How many times is God called “Yahweh” in the Bible?‘
2. Part of the reason for this might be because, under the New Testament, God has given all power and authority to his son, Jesus (Mat. 28:18), who reigns for him (1 Cor. 15:24-28), so now the focus is on the name of Jesus (Phil. 2:9-11).