Hello. The color of the photo in the program and after export is very different. In the program, photos are paler, but in JPG format they are saturated. In the export settings, I change the color profile (sRGB, Adobe RGB, ProPhoto RGB), but this does not affect the result in any way. In Photoshop, this problem is solved by setting the "RGB monitor" profile. I didn't find this setting in Lightroom. The program is installed on an MSI Prestige laptop. Thank you for any help. I have already reviewed all the program settings several times.
This sounds like a defective monitor profile and/or using applications without color management to view the exported files.
Lightroom and Photoshop are color managed, and use the monitor profile (which contains a description of the color response of your monitor) to display correct colors. Images are converted from the document profile to the monitor profile to display correctly on screen.
Setting the working space in Photoshop to Monitor color disables color management, which is something you do not want to do, and you're just sweeping the problem under the carpet. Set the PS color settings back to default.
Windows 10 is known to install low quality profiles from monitor manufacturers when doing updates. These profiles are often defective out of the box, and you may well have a defective profile.
As troubleshooting, and as a possible temporary fix, try setting the monitor profile to sRGB (use Adobe RGB if you have a wide gamut monitor).
With Lightroom and Photoshop closed, press the Windows key + R, type colorcplin the box and press Enter. Add the sRGB profile, and set it as default.
If this fixes the issue, it is recommended that you calibrate the monitor with a hardware calibrator.
This will also create and install a custom monitor profile that accurately describes your monitor.
Also note that no native Windows applications (except the Edge Browser) are color managed, and will not display correct colors. This includes Photos, Paint, File Explorer, Desktop.
I suggest that you use a color managed viewer to view your exported work, like FastStone (free for personal use) or ACDSee. In FastStone you have to go to Settings > CMS to enable color management, both boxes must be checked.