GPU 3D crash
I have a 32g computer ram. and 12g video ram card. ive tried so many things ive been told to try and the one thing i cant change is go into DAZ and render setting and go to advanced tab. Check Allow CPU Fallback. the advanced button or tab or in windows isnt there. ive switched my nvidian to studio and updated my drivers. if tried altering other settings in my computer and in daz but i can not get this to work. it crashes on me every few minutes or if i try and iray the model and a light. i dont have a dforce hair on my model. or anything crazy done. Computer specs, Processor 13th Gen Intel(R) Core(TM) i7-13700KF (3.40 GHz) installed RAM 32.0 GB (31.8 GB usable) graphics card NVIDIA GeForce RTX 4070 (12 GB)

Comments
Are you looking in the right place for the fallback option? It's located in the Render pane under the Hardware tab.
DS crash might come from various causes, e.g. shortage of RAM or VRAM, Nvidia or CUDA driver incompatibility, GPU hardware failure, faulty plugins, problematic assets, etc.
Did you see a message reporting a fatal error when DS crashed ? You could save the crash report and give it an analysis 1st of all ~~
Please tell us exactly what version of Daz Studio you are running. The best way to give complete information is to go to the Help menu in Daz Studio and select About Daz Studio...
A box will pop up with all the details. Take a screenshot of that pop up and save it on your computer. Then, in this forum thread, select Attach a file then click the Browse button, navigate to the screenshot you saved, select it and Click Open. Then click the POST COMMENT button.
Tell us what NVIDIA studio driver version (the number) you have installed. The latest is not always the greatest.
If you are looking for an Advanced tab in the Render Settings pane, you may be following obsolete instructions. That's part of why I asked you to let us know what version of Daz Studio you are running. The Allow CPU Fallback setting is on the Hardware tab in both DS 4.24.0.4 and DS6 versions, when the NVIDIA Iray (MDL) Render Engine is selected. I have attached a DS 4.24.0.4 screenshot of my Render Settings. I have a custom layout. Your layout probably has Render Settings in a different section of the layout, but that doesn't matter. I hope this helps you locate the CPU Fallback option.
CPU Fallback is really kind of a last resort, though. CPU rendering will be MUCH slower that rendering with your RTX 4070. It would be a good data point, though, to know if your scene renders OK with the CPU. It is much better to try to resolve the cause of your crash. Lots of people are here willing ot help. As crosswind said, if you get a crash report, save it. That is a good place to start.