Capture One provides two generic conversion options. The Generic D50 option matches most third-party implementations such as that used by Delt.ae by Picturae and LCMS by Marti Maria and converts Lab values using D50 as the white point.
Generic (media white) can be used to match colors while avoiding chromatic adaptation. However, colors must be measured under the light source of the intended color space profile. For sRGB and Adobe RGB (1998) this is D65.