How to send an edited RAW photo to a lab for processing without the RAW file automatically being converted to jpeg & loss of data.
An edited RAW file would need to be interpreted by exactly the same software you used to initially edit it. This is just not practical.
If you export as a TIFF with your camera's .icc profile embedded [or potentially pre-converted to sRGB], you will lose no data & the receiver will be able to extract the image you intended. The only issue with TIF is they can be really quite large files - RAW 25MB, TIF 190MB
The standard accepted formats for printing would also include .PNG [totally lossless] or even .JPG at 100% quality. [between 6 - 16MB]
If your printer expects to receive CMYK files, then RAW is out of the question. If they accept either, I'd stick to sRGB as their pre-print conversion will likely be better attuned to their workflow.
I've produced prints at 120x80 cm from .JPG with no visible loss of quality whatsoever other than the slight 'stretch' of printing at 150 dpi rather than 300.