Error: attempt to index field 'popup_layout' (a nil value)

Hi folks, after installing the plugin via Packer, I am getting the following error on running `:ChatGPT` command
```
Error executing Lua callback: ...acker/start/ChatGPT.nvim/lua/chatgpt/flows/chat/base.lua:47: attempt to index field 'popup_layout' (a
nil value)
stack traceback:
...acker/start/ChatGPT.nvim/lua/chatgpt/flows/chat/base.lua:47: in function 'init'
...packer/start/ChatGPT.nvim/lua/chatgpt/common/classes.lua:88: in function 'new'
...acker/start/ChatGPT.nvim/lua/chatgpt/flows/chat/init.lua:13: in function 'open_chat'
...nvim/site/pack/packer/start/ChatGPT.nvim/lua/chatgpt.lua:34: in function 'openChat'
...m/site/pack/packer/start/ChatGPT.nvim/plugin/chatgpt.lua:2: in function <...m/site/pack/packer/start/ChatGPT.nvim/plugin/ch
atgpt.lua:1>
```

Packer Installation snippet:
```
use({
"jackMort/ChatGPT.nvim",
config = function()
require("chatgpt").setup()
end,
requires = {
"MunifTanjim/nui.nvim",
"nvim-lua/plenary.nvim",
"nvim-telescope/telescope.nvim"
}
})
```

If anyone familiar with the issue, kindly help. Thanks in advance : )

Start with lua/chatgpt/flows/chat/base.lua at line 47, then trace initialization from lua/chatgpt/flows/chat/init.lua and the setup call in the reported Packer configuration. Reproduce the error with :ChatGPT and determine what is missing from popup_layout; done means the command opens without this callback error.

Written by the indexing model from the issue text.