Primordial black holes (PBHs) as a potential dark matter (DM) candidate, have gained renewed interest due to their testability through gravitational wave (GW) observations [1, 2]. Given the existing constraints on PBH [3], they may comprise all of DM only in the asteroid mass window 10−16M . mPBH . 10−11M. Yet, heavier PBHs may be related to the seeding of cosmic structures [4–6] including the high redshift surprisingly luminous galaxies observed by the James Webb telescope [7– 9]. After the first detections of black hole (BH) binaries by LIGO [10], speculations of their possible primordial origin were presented [11–13]. The subsequent analyses of the observed binary population [14–16] indicate that many of these BHs are likely to have an astrophysical origin [17–20], while the observed merger rate suggests that stellar mass PBHs cannot account for more than a percent of all DM [17, 21–26]. The next generation GW observatories can probe PBH binary populations across a broad parameter range [27, 28]. Gravitational lensing has provided important probes of PBH DM, with 10−11M . mPBH . 30M PBHs constrained by stellar microlensing [29–35] and heavier PBHs by the lensing of type Ia supernovae [36, 37] or GWs [38]. At high masses, mPBH & 100M, the most stringent constraints arise from the accretion of baryons into PBHs [39–45]. The search for PBHs and other compact astrophysical objects in the stellar mass range can be conducted through GW lensing, with next-generation GW observatories, such as the Einstein Telescope (ET), having the potential to confirm or exclude the primordial origin for the observed BH mergers [38, 46–49]. Conventional optical microlensing searches rely on the lens transiting through its Einstein radius and become challenging when the transit time exceeds the duration of the experiment. GW microlensing, on the other hand, relies on the interference of the multiple paths the GW takes around the lens [50] allowing for the detection of much heavier lenses. Although various different DM substructures have been considered as lenses [51–54], the expected rate of such events has been shown to be low [55].