Sounds like you selected the 2024 Warlock, which chooses its subclass at level 3. If you wanted the 2014 Warlock which chooses it at level 1, you'll need to remove the existing class and add the other one instead. (Make sure you have 2014 Core Rules enabled for that character in order to select that class.)
When I multiclassed as a warlock from a rogue it doesn’t let me apply my otherworldly patron as a lvl 1 warlock, is this a bug or am I stupid?
Sounds like you selected the 2024 Warlock, which chooses its subclass at level 3. If you wanted the 2014 Warlock which chooses it at level 1, you'll need to remove the existing class and add the other one instead. (Make sure you have 2014 Core Rules enabled for that character in order to select that class.)
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