You may be able to stream without lag with different OBS settings but it would help to know what cpu and graphics card you have on that laptop.
Dropping the FPS to 30fps instead of 60 (if you have it set to 60) can help a lot (in the 'video' section of settings).
In the 'output' section of settings, if your GPU (if you have an NVIDIA GPU that supports hardware encoding) you'll see an option for Hardware (NVENC) under 'encoder'. If not with an Intel CPU you should see an option for 'quicksync' as 'cbhours' stated which is another form of hardware encoding - quicksync has been around since 2011 so unless your cpu is very old you should see that. Quicksync uses a separate section of an Intel cpu dedicated to encoding so it doesn't slow down the cpu itself. If both are an option try them both to see what works best.
If you are using options in OBS for overlay and background etc these can be a big strain on the cpu also. Seeing how your stream looks lag wise w/o those would be something to try.
Check to see what is running on the latop on start up and see what you can disable also. Some anti virus programs can dog a cpu for instance. You really want to minimize any background processes and other programs that may be running unnecessarily.
Check what you have set for the bitrate also which needs to be high enough to support what you are sending to the site.
NVIDIA has an OBS settings guide here which shows the general bitrate you want for the stream you are sending -
https://www.nvidia.com/en-us/geforce/guides/broadcasting-guide/
Hardware encoding takes the strain of encoding the video away from the cpu.
If you find you actually need a new laptop I would look for something with an AMD 4800H cpu (the H models have greater power handling do not get a U model) and an NVIDIA GTX 1660 TI video card or better (better would be something starting with RTX) and 16GB of ram with an ethernet port so you do not have to depend on wifi.
The 1660 TI or better cards all have an NVENC(new) setting available in OBS which supports multiple 1080/60 webcam streams at the highest quality without issue so imo this is the route to take. The more expensive RTX cards support gaming features but the encoder is the same as with the 1660 TI to the best of my knowledge.
Best of luck to you.
