from diffusers import AutoPipelineForText2Image
import torch

device = "cuda" if torch.cuda.is_available() else "cpu"

pipeline = AutoPipelineForText2Image.from_pretrained('black-forest-labs/FLUX.1-dev', torch_dtype=torch.bfloat16).to(device)
pipeline.load_lora_weights('dougduggarts/steven-seagal', weight_name='StevenSeagal.safetensors')
image = pipeline('StevenSeagal wearing black tactical glasses and full SWAT gear.Holding a script in his hands. Busting through a door into a building.').images[0]

For more details, including weighting, merging and fusing LoRAs, check the documentation on loading LoRAs in diffusers