Download & unzip the filter files

Download DGTonemap and DGHDRtoSDR from the developer's site or here to get the latest versions including DGHDRtoSDR v1.4.

(Make sure to put x64 versions if your system is x64.)

DGTonemap supports AviSynth only while DGHDRtoSDR supports both AviSynth and VapourSynth (dual mode).

Recommended places for the filters are as follows:

%settings_dir%Plugins\AviSynth\DGTonemap\DGTonemap.dll
%settings_dir%Plugins\Dual\DGHDRtoSDR\DGHDRtoSDR.dll

You can find your %settings_dir% by clicking Tools > Folders > Settings menu.

Of course, you can always save the filters in other places. But somewhere under %settings_dir% is recommended in order to preserve the program folder structure as it is shipped.

Now open an empty StaxRip window and do the following setup.

AviSynth filters

Open and edit AVS profiles:

DGTonemap

Put DGTonemap item under the [Color] section with a code snippet as follows:

HDR to SDR | DGTonemap =
    LoadPlugin("%settings_dir%Plugins\AviSynth\DGTonemap\DGTonemap.dll")
    $select:msg:Select the Tone Map you wish to use;DGReinhard|DGReinhard();DGHable|DGHable()$

DGHDRtoSDR

Add the following item related to DGHDRtoSDR under the [Color] section:

HDR to SDR | DGHDRtoSDR =
    LoadPlugin("%settings_dir%Plugins\Dual\DGHDRtoSDR\DGHDRtoSDR.dll")
    DGHDRtoSDR(mode="$select:msg:Select Transfer Function;Perceptual Quantizer|pq;Hybrid Log Gamma|hlg$", white=$enter_text:Enter Overall Brightness in integer (max 2,000 for PQ, max 10,000 for HLG)$)

VapourSynth filters

Change the filters type from AviSynth to VapourSynth by clicking Filter Setup ⇨ VapourSynth:

Open and edit VS profiles:

DGHDRtoSDR

Add the following item related to DGHDRtoSDR under the [Color] section:

HDR to SDR | DGHDRtoSDR =
    core.std.LoadPlugin(r"%settings_dir%Plugins\Dual\DGHDRtoSDR\DGHDRtoSDR.dll")
    clip = core.dghdrtosdr.DGHDRtoSDR(clip, mode="$select:msg:Select Transfer Function;Perceptual Quantizer|pq;Hybrid Log Gamma|hlg$", white=$enter_text:Enter Overall Brightness in integer (max 2,000 for PQ, max 10,000 for HLG)$)

You can always edit the profiles code by referring to the StaxRip macros document.