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('Keltezaa/kristen-stewart-flux', weight_name='Kristen_Stewart_Flux.safetensors')
image = pipeline(' This is a high-resolution photograph of a woman standing in a cafe,  brown hair cascading over her shoulders, wearing a chic black dress, looking at the viewer').images[0]

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