Cannot solve

[sugyan]

https://yaneuraou.yaneu.com/2020/12/25/christmas-present/
mate7.sfen:9

ln3kgRl/2s1g2p1/2ppppn1p/p5p2/6b2/P3P4/1+rPP1PP1P/1P4S2/LNSK1G1NL w GPbsp 50:
   9   8   7   6   5   4   3   2   1
+---+---+---+---+---+---+---+---+---+
|  l|  n|   |   |   |  k|  g|  R|  l| a
+---+---+---+---+---+---+---+---+---+
|   |   |  s|   |  g|   |   |  p|   | b
+---+---+---+---+---+---+---+---+---+
|   |   |  p|  p|  p|  p|  n|   |  p| c
+---+---+---+---+---+---+---+---+---+
|  p|   |   |   |   |   |  p|   |   | d
+---+---+---+---+---+---+---+---+---+
|   |   |   |   |   |   |  b|   |   | e
+---+---+---+---+---+---+---+---+---+
|  P|   |   |   |  P|   |   |   |   | f
+---+---+---+---+---+---+---+---+---+
|   | +r|  P|  P|   |  P|  P|   |  P| g
+---+---+---+---+---+---+---+---+---+
|   |  P|   |   |   |   |  S|   |   | h
+---+---+---+---+---+---+---+---+---+
|  L|  N|  S|  K|   |  G|   |  N|  L| i
+---+---+---+---+---+---+---+---+---+
Side to move: White
Hand (Black): G1 P1
Hand (White): b1 s1 p1
Ply: 50

as is: infinite loop
to be: ["3e7i+", "6i7i", "B*5g", "7i6i", "S*6h", "6i5h", "S*6i"]