The default location is /DCIM in phone's internal storage (may be identified as /sdcard/DCIM or /emulated/o/DCIM). This is different from external SD, which would be /extsdcard/...). If it's missing, then try Dr.Fone for Android, as suggested. If you go the Dr.Fone route, minimize app usage, as recovery programs have the greatest chance of success if the storage area has not been written to (possibly overwriting the files you are trying to recover).
Be aware that Dr.Fone is not free, but the analysis report to determine if it can help is. Before buying, check online for discount codes - they are commonly available and can save you up to 50%. GL!