I pasted the following SGF file into my library:
(;FF[4]
GM[1]
AB[bp][bq][cq][dd][dq][eb][ec][ed][ef][ei][ej][er][fj][fr][gk][gm][hk][jd][jn][kl][km][le][lf][lh][lk][mj][mq][nc][nr][oh][oq][os][pd][pn][pp][pq][qd][qh][ql][rd][rf][rg][ri][sh]
AW[bc][be][bf][bo][cd][ci][cm][cp][db][dc][dp][em][eq][fh][fi][fk][fn][fq][gj][gp][gr][hj][in][jl][jp][kj][kk][md][me][mf][mm][mp][mr][nh][no][np][nq][oi][op][pf][ph][qe][qf][qg][qi][qj][rj]
PL[W]
)
As you can see there are a bunch of setup properties to add some stones. Then there is a PL property to mark white to play. However, when I go to Anaylize Game, OGS only allows placing a black stone for the first move. It appears to me that the SGF parser does not recognize the PL property.